Getting Error when reading a file - python-2.7

Question

I'm getting a simple but confusing error when trying to create a login worker
via python.
Here's the error i'm getting.
Traceback (most recent call last):
File "stratixlogin.py", line 87, in <module>
main()
File "stratixlogin.py", line 78, in main
login_worker()
File "stratixlogin.py", line 51, in login_worker
data = f.read()
ValueError: Mixing iteration and read methods would lose datanter code
Here is where the Error is occuring:
with open("global_users.txt", "r") as f:
for line in f:
data = f.read()
if data == username_ask:
print(G+"Success!")
password_ask = raw_input(O+"Password:"+W+" ")
with open("global_passwords.txt", "r") as f:
for line in f:
data = f.read()
if data == password_ask:
print(G+"Success!")
else:
print(R+"Incorrect Password!")
else:
print(R+"No Users Found!")
I am not sure what the error is here, But i am confused on how to fix this. Any Ideas?

Answer 1

You can't mix iterating through the lines of the file (the for loop) and read().
This is enough:
with open("global_users.txt", "r") as f:
for data in f:
if data == username_ask:
print(G+"Success!")
password_ask = raw_input(O+"Password:"+W+" ")
with open("global_passwords.txt", "r") as f:
for line in f:
data = f.read()
if data == password_ask:
print(G+"Success!")
else:
print(R+"Incorrect Password!")
else:
print(R+"No Users Found!")